Transanal Total Mesorectal Excision in Mid-Low Rectal Cancer: Evaluation of the Learning Curve and Comparison of Short-term Results With Standard Laparoscopic Total Mesorectal Excision

BACKGROUND: Ever since transanal total mesorectal excision was introduced by Sylla and Lacy in 2010, it has become more popular among colorectal surgeons. However, some surgeons hesitate to use it, because this novel approach differs greatly from laparoscopic total mesorectal excision and requires a long learning curve. OBJECTIVE: This study analyzed the learning curve of transanal total mesorectal excision procedure and compared the different phases of transanal total mesorectal excision with laparoscopic total mesorectal excision. DESIGN: This is retrospective case-control study. SETTINGS: We used data from the approved colorectal cancer database of the Sixth Affiliated Hospital of Sun Yat-sen University. PATIENTS: The patients involved in this study underwent transanal total mesorectal excision performed by a single surgeon (L.K.) or underwent laparoscopic transanal total mesorectal excision performed by experienced surgeons. INTERVENTIONS: Transanal or laparoscopic resection of mid-low rectal cancer was conducted. MAIN OUTCOMES MEASURES: Perioperative complication and resection margin were measured. RESULTS: A total of 342 patients were included in both groups. The learning curve of transanal total mesorectal excision was divided into 3 phases. Data show that demographics and tumor characteristics were not significantly different between the matched groups. Indeed, during phase 1, only operative time was longer than in the laparoscopic group, whereas, during phase 2, results from the transanal group were comparable with the laparoscopic group. Results show that, during phase 3, operative time, intraoperative blood loss, and postoperative hospital stay were all lower than in the laparoscopic group. Local recurrence occurred in 3 patients during phase 1 and in 1 patient during phase 2. LIMITATIONS: This study was a small retrospective study and focused on just 1 surgeon performing transanal total mesorectal excision. CONCLUSIONS: Short-term and histopathologic outcomes are similar compared between a transanal group and matched laparoscopic group. Transanal total mesorectal excision also provided good oncologic outcomes. See Video Abstract at http://links.lww.com/ DCR/B450.

Automated summary

The study compared the learning curves and outcomes of transanal total mesorectal excision with laparoscopic total mesorectal excision, finding that in different phases of the learning curve, operative time, intraoperative blood loss, and postoperative stay were significantly lower in the transanal group, with similar short-term and histopathologic outcomes between the two groups.